There goes the prom queen, clad in a column of red à la Emma Stone at last year's Academy Awards.

And here comes the holiday partygoer, flirting with her leg in a thigh-high slit à la Angelina Jolie on the 2012 Oscar red carpet.

In the fashion world, the Oscars hit at an opportune time: Just before prom and wedding seasons kick in. So it's no surprise that the dresses paraded on the Academy Awards red carpet have an effect on what twirls across the gym floor and down the church aisle — and, months later in the special-occasion calendar, under the mistletoe.

But this year, the Oscar Effect will reach even more wardrobes, those of young girls and older women, as the youngest- and oldest-ever best actress nominees, Quvenzhané Wallis and Emmanuelle Riva, vie for the trophy — and inject freshness into two wedges of the formal wear market that are woefully lacking, or so stylists, designers and editors hope.

"It could be a pivotal year," says Dan Rentillo, design director for David's Bridal, who, for fall 2011, created an ankle-baring, full-skirted wedding dress inspired by Steinfeld's Marchesa confection. Women Riva's age — 86 on Oscar day — are looking for sartorial role models "because all of our role models are much younger."

At the other end of the age spectrum is the 9-year-old Beasts of the Southern Wild star, who has sparkled all awards season in her shiny, knee-length dresses and glittery ballet flats. "People are going to look to her and say, 'How fun! I can do that for my daughter,' " says Wallis' stylist for the past year, Los Angeles-based April Steiner. "It's inspiring."

And not just to parents. "You can absolutely be sure designers are going to be watching how they can transfer" what walks down the red carpet, says Marshal Cohen, chief industry analyst at The NPD Group, a market research firm. Because of their historic milestones, Wallis and Riva "will get an extra set of eyes, and more (media) coverage will translate into more attention by retailers and designers" — and, perhaps, flower girl and mother-of-the-bride dresses that borrow from the carpet, either piecemeal or whole, well, cloth.

The industry effect, especially thanks to Wallis, is already apparent. "Designers that do not make children's clothes are knocking on our door," says Steiner. Wallis is her youngest-ever client. "They're seeing, 'Oh, my god, there is a market for this," because what's out there for girls barely old enough to spell "Oscar" is scarce, and stagnant. "It's all the same, with the sash and the bow. It's, 'Can you do something a little bit more fun?' "

One designer who has heeded the crinoline challenge is L.A.-based David Meister, whose youngest client had been 16 or 18 before he put Wallis in four dresses this season (so far), including a sleeveless bright purple, ballgown-skirted frock she wore to the Oscar nominees luncheon. After the success he's had — Wallis has gotten raves for her sweet style — Meister is considering a little girls' line.

"It's certainly opened a door," says Meister, who's sent around 15 dresses down the Oscar red carpet, on women from Diane Lane to Jane Seymour. Not surprisingly, he's coy when asked whether another Meister-Wallis union will take his tally to 16. "You never know!" he says. "Let's just say we are working together."

Steiner deepens the mystery: "I can tell you we just want it to be a really, really big surprise." That said, "it won't be a huge departure from what we've seen."

To wit: Wallis will be toting one of her now-trademark doggy purses, but her first custom piece. "It is going to be something very, very special, befitting as formal and elegant as the Oscars are," says Diane Calvanico, sales manager for the purse's brand, New York-based Poochie and Co. "We're going to try to load him up with some bling."

The response to Wallis and her kennel of 50-plus Poochies has been "unprecedented," says Bob Frankel, COO of Poochie's parent company, Cudlie Accessories. Every time she's seen with a new dog, stores will call asking to carry that breed (the pups generally go for $12 to $15 each). The company is getting calls from retailers they don't do business with and is showing double-digit sales growth. "You could not have scripted this," Frankel says.

Meister seems enamored of his new market. "Little kids are very honest, which I love. There's no tap-dancing around," he says. Besides, "it's much easier fitting a 9-year-old than an adult woman. There are no issues like, 'Is this going to fall out?' "

"They don't have the bubbies yet. They don't have the rigmarole of 'my cellulite,' " says Steiner. "My only challenge is she's growing so fast," from a 7-8 a year ago to, now, a 12. "She's just so unaffected by anything and just so free-spirited and wants to just have a good time. It's really fun to be in those fittings when it's just a dance party and snacks."

"What Quvenzhané is doing on the red carpet is really an inspiration for young girls because that's how they should dress at that age," says Nikki Pennie, a British-born, L.A.-based stylist who has dressed Kate and Pippa Middleton. "This girl is starting to be a little bit of an Elle Fanning."

With young nominees in the past, "the big fashion houses will come in and offer to make them something, and sometimes they lose their character and their personality," says Susan Ashbrook, the author of Will Work for Shoes: The Business Behind Red Carpet Product Placement, who has been uniting designers and celebrities for the Oscars for more than 20 years. "I hate to see when their dress overwhelms them." Her favorite Oscar tween togs? Tatum O'Neal and her Nolan Miller tuxedo in 1974. She was 10 going on 50, a child of Hollywood, and "she carried it off with such pride."

When it comes to putting older women on the red carpet, the sartorial pickings may be slim, as Hollywood stylist Estee Stanley says, but there are advantages. "They've been around the block," says Ashbrook. "They know what colors work for them," they know what their assets are "and they work it." (Think of Elizabeth Taylor and her decolletage-revealing dresses.)

Never more so than today. Thanks to the likes of Helen Mirren, Glenn Close and Meryl Streep, "in the last 20 years, people get it," says Meister, who has dressed Mirren. "It's not all of sudden you reach 50 and you fall apart and you want to dress dowdy," whether you're standing on a red carpet or dancing in a banquet hall. The fitted jacket, the mauve chiffon skirt and dyed-to-match sensible pump — "no, it's over." About 15% to 20% of Meister's business caters to mothers of the bride, and he's seen the market change "dramatically," just as the expectations of what over-50 women should wear on the red carpet have been overhauled.

For older women, it's about creatively concealing flaws (real or perceived) and highlighting strengths. Ashbrook teamed with Georges Chakra and Mirren for the Oscar presenter's 2008 dress. Mirren was 62. "She said to him, 'Hey, I really feel more comfortable wearing sleeves but don't want to be matronly.' " The solution? Elegant, three-quarter crystal-encrusted sleeves that accented her cinched, rich ruby gown.

Still, it can be tough to stand beside the gym-chiseled bodies. "The older an actress gets, the more insecure she feels because she, of course, is competing on the red carpet next to girls who are a third her age if not more, so the pressure is even bigger," says Brian Rennie, creative director of Basler, who recently put the 62-year-old Seymour in a playful pink halter gown for the Art Directors Guild Awards. "You have to be psychiatrist more than designer," he says.

During his tenure as Escada's designer, Rennie dressed a 72-year-old Deborah Kerr and an 87-year-old Gloria Stuart in comfortable but chic separates for the Oscars (a tunic and pants for Kerr, a jacket and skirt for Stuart) in soft turquoise and teal.

Riva has certainly adhered to Meister's edict, staying away from mauve and turning to teal (as per her appearances at last year's Cannes Film Festival and Amour Paris premiere) and shunning chiffon in favor of patterned, jewel-toned coats (such as at this year's National Board of Review Gala).

Old or young, Meister bristles at the idea of "age-appropriate" dressing. "Who wants to age appropriately? Yech. That scares me," he says. "If it fits and it looks good, it's age-appropriate."